Core-drilling head



Sept. 18, 1 928. 1,685,045

7 c. s. CLARKE CORE DRILLING H E AD Filed June a, 1927 I 31 ou Hot mow-um scat: vulva gown".

Patented Sept. 18, 1928.

UNITED STATES PATENT OFFICE.

CLEMENT S. CLARKE, OF SHREVEPORT, LOUISIANAv ASSIGNOB TO OIL CITY IRON WORKS, OF SHREVEPORT, LOUISIANA, A CORPORATION OF LOUISIANA.

CORE-DRILLING HEAD.

Application filed June 8, 1927. Serial No. 197,445.

This invention relates to improvements in core drilling apparatus. I

The primary object of this invention 15 the provision of an improved core drill head embodying a novel arrangement of cutters for most efficiently cooperating with the cutter head body in providing a core of even cylindrical formation without disintegration thereof.

A further object of the invention is the provision of an improved core drill head used in connection with rotary drilling equip ment, for the securing of true core cuts of sands, shales, gumbo clays and rocks; the improved head including lateral cutters which perform all of the work in cutting away the core without liabllity of water reaching the core to disintegrate the same.

A further object of this invention 1s the provision of a core head including a. body with a core receiving passageway therein provided with cutting edges therein to shave the core to a uniform circumference; such cutting surfaces being very effective when securing cores of gumbo or clays.

A furtherob'ject of this invention is the provision of an improved core drill head embodying a novel arrangement of initial cutting and reaming blades.

A further object of this invention is the provision of an improved core drill head embodying a body with lateral extending cutting blades and a lower edge so shaped as to permit the shaping of the core to be accomplished entirely by the lateral cutting blades on the body.

Other obiects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawing, forming a part of this specification, and wherein similar reference characters designate corre sponding parts throughout the several views,

Figure l is a perspective bottom view of the 5 improved core drill head.

Figure 2 is a vertical sectional view taken through the lower end if 'a drill stem with the improved core head thereon and its drilling assemblage.

Figure 3 is a side eleyation, partly in section, showing details of the improved core head.

Figure 4 is abottom plan view of the improved eore drill head, showing the improved 55 details of construction thereof.

In the drawing, wherein for the purpose of illustration is shown but a preferred embodiment of the invention, the letter A may generally designate the improved core drill head, which is adapted to be coupled either directly to the lower end of a drill stem B, or to the drill stem B thru the intermediary of a connecting hub or coupling C. The hub C and core drill head A have associated therewlth a core barrel D, a water guide barrel E, and a core restrainer F.

Referring to the general assemblage of the core drillhead A in connection with the other drilling apparatus, as illustrated in Figure 2, it is to be noted that the core drill head A includes a body 10, which thru the lower end thereof is provided with a cylindrical shaped passageway 15, which determines the diametcr of the core. Above the passageway 15 the interior of the body 10 is enlarged, at 16, providing an upwardly facing annular shoulder 17. Above the passageway 16. the body 10 is provided with an upwardly extending tapered screw. threaded socket 20, on an upwardly increasing diameter. In the passageway 16 of the shoulder 17 the core restrainer F is adapted. to

rest, and the hub C is screw threaded at its end 21 into the socket 20. The drill stem E is screw threaded into the upper end of the hub portion of the coupling C, at 23, and the coupling C has the core barrel D resting therein on a shoulder 24, and also has the guide barrel E detachably connected at 25; the coupling C having transverse ports 28 therethrough immediatelyi above the drill head A, through which water passes from the water space 29 in the drill stem, to a point above the drill head A, where it may flow downwardly along the drill head A as permitted by the drill head and well casing.

As to the improved core drill head A, the body 10 as above described is hollow. The body 10 includes an upper portion 30, of hollow cylindrical formation, and the lower portion thereof is in the form of a hollow truncated conoid, and thus the lower end of the body 30 is provided with a convex arcuated surface 31 meeting flush with the external periphery of the upper cylindrical portion 30; the convex surface 31 extending downwardly in a preferably parabolic curve to the lower edges of the body 10, as would be the case in forming an inverted hollow truncated conoid.

The body 10 is provided with a preter ably integral set of initial cutting blades 40, 41 and 42. which may be three in number, although the number may be iess or more, if desired. 'lhes'e initial cutting blades -10, all and 42 are arranged at lit) about the body 10, and they extend laterally from the ex ternal convex surface 31 of the body 10, for the length of the trum-ated conoidal por tion of the body 10. The blades 40, ll and 42 provide cutting edges it which preferably lie in the same plane at the very lowermost portion of the body 10, and entirely perform the work of cutting away the earth or other formation to provide the core which enters the passageway 15. The cutting edges fl extend from the passageway 15 laterally to the outer side edges 45 of said initial cutting blades, all of which side edges 45 are vertically arranged flush with the external surface of the cylindrical portion 30. as well illustrated in the various figures of the drawing. Thus the bore cut by the initial cutting blades 40, 41 and 42 in maximum diameter is equal to the diameter of the external surface of the cylindrical portion of the body A set of reaming cutting blades 50, 51 and '52 are provided in laterally extending relation on the body 10, in length extending from preferably the top edge 54 of the body 10, and extending along the cylindrical portion 30, andp'artiallydownwardly along the truncated conoidal portion of the body 10; said reaming blades 50, 51 and 52 terminating at their lower ends in cuttingedges 60, all of which are disposed in the same plane, and in a plane spaced above the plane of the initial cutting blades. The cutting blades 50, 51 and 52 have the lower cutting edges 60 thereof extending transversely the entire distance from the convex surface 31 to the outer side surfaces 65, and the cutting edges 60 cut a bore in the earth formation of a larger diameter than the bore cut by the initial cutting blades, as is quite apparent. The width .of the reaming cutting blades 50, 51 and 52 are reduced at towards the upper portions of said blades, so that the side edges of the said upper portions of the reaming cutting blades will not contact the walls of the bore formed by the reaming cutting blades, to facilitate the drilling operation and removal of the drill head.

It is to be particularly noted that the initial cutting and reaming cutting blades are all inclined diagonally on the body 10, sloping from their upper ends longitudinally downward in the direction in which the core drill head is rotated. The lower ends of all of the cutting blades of both sets are more acutely inclined at in the direction of rotation of the drill head than the upper portions thereof, and the cutting edges 44 and 60 of said cutting blades, in length, are arcuated; the leading and trailing sides of the essors blades above the cutting edges being convexly arcuated as illustrated in the drawing. This forms a very strong and durable blade construction.

The blades of both sets are preferably integral on the body it), and the same may be of chrome nickel steel with the. cutting ends of the blades tipped with stellite, or the blades may be otherwise connected on the body and formed of suitable material for drilling purposes.

An improved feature of the improved core drill head is the fact that the bottom edge of the body 10 does not. perform any cutting operation into the earth or rock formation in order to form the cylindrical core which enters the passageway 15. This core cutting operation is performed in the first instance entirely by the cutting blades 40. 41 and 42. The material at the lower end of the body 10 from the trailing edge of each of the initial cutting blades 40, 41 and 42 slopes upwardly at an acute angle to the plane in which the cutting edges of the blades 40, 4-1 and 42 dig into the earth or rock formation, thus providing flat edges 80, 81 and 82 between the three blades of the set of initial cutting blades, each of which slopesfrom the trailing side of the cutting edge of its foremost cutting blade, at an acute angle to the plane of the cutting edges 60, and terminates at the leading side of the next rearmost cutting blade, at a location spaced above its cutting edge 60. This is well illustrated in Figure 3 of the drawing, showing the edge which at its upper end sloped from a. plane above the cutting edge 60 at the leading side of the cutting blade 40, downwardly towards the plane of the cutting edges 44, and terminates at the trailing side of the initial cutting blade 42, preferably in the same plane as the cutting edge 44 thereof. These edges 80, 81 and 82 present flat, or substantially horizontally broad surfaces which may seal against the top of the formation cut down by the initial cutting blades. to prevent water from disintegrating the core. The slope of the edges 80, 81 and 82 may be inclined proportionate to the angular degree of penetration of the drill head incident to the initial cutting blades operating in earth formation. vIt is to be particularly noted from Figure 4 of the drawing that the surface of the edges 80, 81, and 82, in plan view, presents the form of a half-crescent or the fragment of a crescent, depending upon the number of initial cutting blades employed; the surfaces of said edges gradually widening from the trailing sides of the initial cutting blades to the leading sides of the adjacent cutting blades.

In order to shave the core even, it is preferred to place in the passageway 15 a number of scrapers 90, which may be formed by striking up the material of the body 10 facing in the passageway 15 to a slight projeclltl tion into the passageway 15, as illustrated in Figure 4.

The operation of core cutting will be well understood by the art. The initial cutting blades of applicants novel core drill head out the core, performing all of the initial work in the formation of the core, and thusinsuring that the annular bottom edges on the body 10 about the passageway 15 will not take away any of the strain and wear incident to core cutting. The bore is first cut to a certain diameter by the initial cutting blades, and subsequently enlarged by the reaming blades, and the core enters the passageway 15, being shaved evenly to cylindrical formation, and as it enters the restrainer F the spring arms 100 move back, and the core enters the core barrel D. The spring arms 100 as is well understood aid in the retention of the core in the core barrel when it is desired to pull the drill equipment.

Various changes in the shape, size, and arrangement of parts may be made to the form of invention herein shown and described, without departing from the spirit of this invention or the scope of the claims.

I claim:

1. In a core, drill head a hollow inverted truncated conoidal body, and a plurality of laterally extending cutting blades on the body having their cutting edges in the same plane at the lowermost end of the body, the body having a passageway therethrough, and the body about said passageway having its lower end margin continuously receding from the trailing side of each of the blades to a location immediately at .the leading side of the next adjacent blade and with said end marginal ed es all located above the cutting.

plane of sai blades, so as to permit the core to be formed entirel by the cutting blades independent of the ower edge of the-body about said passageway.

2. In a core drill head an inverted truncated conodial body having a passageway therethrough, a plurality of laterally extend ing cutting blades on the body having their cutting edges in the same plane at the lowermost end of the body, the walls of the body increasing in thickness from said cutting plane upwardly, the body about said passageway having its lower end margin receding continuously from the trailing side of each of the blades to locations immediately at the leading sides of the next adjacent blades and with said end marginal edges all located above the cutting plane of said blades, and presenting in end elevation a plurality of faces of fragmentary crescent shape between said blades.

3. In an integral core drill head the combination of a body including an upper long cylindrical portion and a lower. tapered portion of gradually decreasing width at the lower end thereof, said body having a pas:

sageway therethrough and the tapered por tion having exteriorly thereon laterally extending blades with cutting edges disposed in a plane below the lower edge of the body and of a width to cut a bore in diameter exactly equal to the diameter of the cylindrical portion of said body.

4. In a core drill head a body having a passageway therethrough and provided with an upper cylindrical portion and a lower tapered portion of gradually diminishing width towards the lower end thereof, said lower tapered portion externally thereon having cutting blades of substantially triangular formation the side edges of which are exactly flush and contiguous with the external sides of the cylindrical portion, said cutting blades havin cutting edges at the lowermost end of sai body all in the same cutting plane.

5. In a core drill head the combination of a hollow body, and a laterally extending cutting blade ext-eriorly on the body having a,

lower cutting edge in the shape of an arc transversely to the body.

6. In a core ing exteriorly thereon a laterally extending cutting blade diagonally inclined longitudinall on the body having a lower end arcuate in the direction of rotation of the body for normal drilling, said cutting blade at the lower end thereof having a cutting edge which curves transversely with respect to the body.

7. In a core drill head a body having a passageway therethrough, cutting blades on the body to cut away the earth to provide a coreand an inverte truncated conoidal lower portion, the lower portion having laterally extending cutting'blades with cutting edges in a cutting plane at the lowermost end of the lower portion of the body, the lower edges of the body between said cutting blades receding from the trailing side of each blade to the leading side of the adjacent blade, and an upper set of reaming blades on the body extending exteriorly laterally therefrom having lower cutting edges in a plane above the plane.of the cutting edges of the first mentioneihblades with the cutting edges of the up er blades partially overlapping with the rst mentioned cutting blades and extending laterally drill head a hollow body hav IOU beyond the effective cutting radius of the first mentioned cutting blades, said second mentioned cutting blades having the upper portions thereof laterally reduced, and the body within the lower end of the passageway having shallow shaving blades projecting into said passageway at a location above e cutting plane of the first mentioned cuttin blades.

10. In a core drill head the combination of a body including an upper elongated cylindri *al portion and a lower convexly tapered portion of gradually decreasing width to the lower'end thereof, said body having a passageway therethrough, a lower Set of blades on the tapered portion extending laterally therefrom having their lower cutting aimmnrl in a plane below the lower edge of said body, said blades and their cutting edges being of a width which will cut a bore in diameter not exceeding but substantially equal to the diameter of the cylindrical portion of said body. and a second set of blades on the body extending along the cylindrical portion and at their lower end overlapping onto the upper part of the tapered portion. the cutting edges of said upper set of blades being disposed in a plane above the cutting edges of the lower set of blades. and the cutting edges and widths ol the upper set of blades being such as to cut a bore which is substantially larger than the bore cut by the lower set of hlades aud larger than the diameter ot the cylindrical portion of said body.

CLEMENT S. CLA RKE. 

